[Modulation of the selective translation of mRNA in cell-free system exposed to tRNA]

The homo- and heterologous tRNA were studied for their influence on the synthesis rate of globin and ovalbumin under simultaneous translation of their mRNAs in the tRNA-dependent cell-free system from wheat germ. In the presence of the fixed concentrations of one of the mRNAs the different amounts of the other mRNA (from 6 up to saturation of the system) were added to the samples. The ratio of the synthesis rate of the translation products after their electrophoretic characterization is determined on the basis of the autoradiogram scanning. The competition among mRNAs in question for some components of translation apparatus has been found: globin mRNA has a higher competitiveness than mRNA for ovalbumin. Modulation of the simultaneous translation of these mRNAs has been shown to depend on the nature of tRNA. The presence of homologous tRNA in the system increases a competitiveness of the corresponding mRNA, but heterologous tRNA reduces it. This regularity is retained in a wide range of the concentration ratios for the both mRNAs.